1. Field of the Invention
The present invention relates to water- and organic-soluble cucurbituril derivatives, their preparation methods, their separation methods and uses, and more particularly, to novel cucurbituril derivatives having various repeating units and internal cavities of various sizes and being soluble in pure water at a neutral pH or in common organic solvents, their preparation methods, methods of separating pure cucurbituril derivatives, and their uses.
2. Description of the Related Art
Cucurbituril is a compound whose preparation was first reported by Behrend et al. in 1905 (Liebigs Ann. Chem. 1905, 339, 1). According to their report, the condensation of glycoluril and excess formaldehyde in the presence of hydrochloric acid (HCl) produces an amorphous solid. Dissolution of the solid in hot concentrated sulfuric acid, dilution of the solution with water followed by slow cooling of the solution to room temperature produces a crystalline material. They wrongly characterized this substance as C10H11N7O4·2H2O, whose structure was, however, not yet identified.
In 1981, this substance was rediscovered by Mock and coworkers. They correctly characterized it as a hexameric macrocyclic compound with composition of C36H36N24O12, which was also confirmed by X-ray crystal structure determination (J. Am. Chem. Soc., 1981, 103, 7367). They named it cucurbituril which we from now on refer to as cucurbit[6]uril. Since then an improved preparation procedure for cucurbit[6]uril has been disclosed (DE 196 03 377 A1).
In 2000, the conventional preparation method of cucurbit[6]uril was improved by Kimoon Kim and coworkers to synthesize and separate cucurbit[6]uril and its homologue cucurbitu[n]uril (n=5, 7 and 8), which was confirmed by X-ray crystal structure determination (J. Am. Chem. Soc., 2000, 122, 540).
The above-described cucurbituril derivatives are compounds of unsubstituted glycoluril monomers and are disadvantageously soluble only in an aqueous acidic solution.
As a cucurbituril derivative with a substitutent other than hydrogen, decamethylcucurbit[5]uril, in which five dimethanodimethylglycoluril units form a cyclic structure by the condensation of dimethylglycoluril and formaldehyde, has only been reported (Angew. Chem. Int. Ed. Engl. 1992, 31, 1475). However, this compound is also soluble only in an aqueous acidic solution.
As described above, the cucurbituril derivatives that have been prepared and known up to now are very limited in terms of their applications because they are insoluble in pure water at a neutral pH or common organic solvents such as methanol.
International Patent Publication WO 00/68232 discloses cucurbit[n]uril having the following formula:
where n is a value of 4 to 12.
In addition, WO 00/68232 discloses substituted glycoluril derivatives having the following formulas:

However, cucurbituril derivatives prepared from the above-described glycoluril derivatives are not disclosed in the cited reference. Also, since the glycoluril derivatives have considerably large substituents, it is quite difficult to synthesize cucurbituril derivatives corresponding thereto due to steric hindrance.